Biomaterial Dispensing Device

ABSTRACT

A device for dispensing biomaterial includes a handle configured to receive a syringe, the syringe including a biomaterial and a threaded plunger, and an engagement pin retained within the handle and slidable between a first position and a second position. The engagement pin is configured to engage the threaded plunger in the first position, the engagement pin is further configured to disengage from the threaded plunger in the second position.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The disclosure is directed to devices and methods for dispensingbiomaterials such as for injecting bone cement, also known aspoly(methyl methacrylate) or PMMA. In particular, the disclosure isdirected to a cement gun for injecting bone cement. Bone cement is ofteninjected to secure prosthetic devices, such as, e.g., artificial jointsand spinal fusion constructs, to natural bone.

2. Related Art

Many devices are available to assist a surgeon with injecting bonecement to secure a prosthesis. These devices, however, suffer from oneor more flaws. For example, some devices are single-use and may not bere-sterilized, increasing surgical costs.

Some devices are incompatible with interchangeable syringe assemblies.If the surgeon uses all the cement in the device, she must halt thesurgical procedure while she mixes additional cement. To avoid this, thesurgeon may have a second device ready. Either solution increasessurgical costs.

Moreover, some syringe assemblies may have inadequate configurations forsecuring the syringe assembly. When using these devices, the syringeassembly may unexpectedly fall out of the device, adding additionalcomplications to an already difficult procedure.

Many devices lack mechanisms for relieving injection pressure in thesyringe. When a device does have such a mechanism, it is usuallydifficult to operate. Quick relief of injection pressure is critical forsafety during a surgical procedure. Bone cement hardens by apolymerization reaction that releases heat. Droplets of bone cement thatcontact soft tissue can result in burns and other injuries that may addadditional complications to an invasive surgical procedure. Preventingstray droplets of bone cement may substantially reduce or eliminate theburn danger posed by bone cement. A surgeon may prevent stray dropletsby reducing injection pressure in the syringe. If the mechanism forreducing injection pressure is clumsy or difficult to operate, thesurgeon may not be able to prevent stray droplets of bone cement fromfalling onto soft tissues. Other complications, such as, e.g.,over-filling a cavity or fracture, may also result from clumsy orcomplicated pressure-relief mechanisms. In contrast, a mechanism forquickly and easily reducing injection pressure may help the surgeonimprove the safety of the procedure by, e.g., preventing stray droplets.

Accordingly, there is a need for a device that is compatible with aninterchangeable syringe assembly and provides an easy-to-use mechanismfor quickly relieving injection pressure in the syringe.

SUMMARY OF THE DISCLOSURE

The disclosure meets the foregoing need and allows use of aninterchangeable syringe assembly and provides a quick release mechanismto relieve injection pressure, which results in a significant increasein safety during a surgical procedure and other advantages apparent fromthe discussion herein.

Accordingly, in one aspect of the disclosure a device for dispensingbiomaterial includes a handle configured to receive a syringe, thesyringe including a biomaterial and a threaded plunger, and anengagement pin retained within the handle and slidable between a firstposition and a second position, the engagement pin configured to engagethe threaded plunger in the first position, the engagement pin furtherconfigured to disengage from the threaded plunger in the secondposition.

The device may include a hole in the handle, the hole may be configuredto hold the engagement pin, the hole may be located so as to permit auser of the device to ergonomically slide the engagement pin between thefirst position and the second position. The device may include a lockingpin configured to retain the engagement pin within the hole, and atleast one ball plunger configured to releasably hold the engagement pinin at least one of the first position and the second position. Thedevice may include a lid having a closed position and an open position,the lid may be configured to retain the syringe within the handle in theclosed position, the lid further may be configured to release thesyringe from the handle in the open position, a hinge pin may beconfigured to connect the lid to the handle, and at least one ballplunger may be configured to releasably hold the lid in the closedposition. The device may include a lid having a closed position and anopen position, the lid may be configured to retain the syringe withinthe handle in the closed position, the lid further may be configured torelease the syringe from the handle in the open position, a hinge pinmay be configured to attach the lid to the handle, a lid pin may belocated in a side of the lid and may be configured to fit into acorresponding hole in the handle, thereby retaining the lid in theclosed position, and a lid spring may be configured to press the lid ina direction substantially parallel to the lid pin axis, the springfurther may be configured to retain the lid pin in its correspondinghole until released by a user of the device. The device may include thelid spring being a coil spring, and the lid spring may surround at leasta portion of the hinge pin. A method for opening the lid of the devicemay include sliding the lid along the hinge pin to compress the lidspring, the sliding resulting in extraction of the lid pin from itscorresponding hole, rotating the lid about the hinge pin so that the lidpin is not aligned with its corresponding hole, and sliding the lidalong the hinge pin until the lid spring is no longer compressed. Themethod may include placing the engagement pin in the second position,placing the syringe into the handle, sliding the engagement pin to thefirst position to engage the threaded plunger, dispensing biomaterial,and relieving injection pressure in the syringe by sliding theengagement pin to the second position.

According to another aspect of the disclosure, a device for dispensingbone cement includes a handle configured to receive a syringe, thesyringe including a biomaterial and a threaded plunger, an engagementmechanism contained within the handle and having a first position and asecond position, the engagement mechanism configured to engage thethreaded plunger in the first position, the engagement mechanism furtherconfigured to disengage from the threaded plunger in the secondposition, a locking mechanism configured to releasably lock theengagement mechanism in the first position, and a release buttonconfigured to disengage the locking mechanism, thereby releasing theengagement mechanism from the first position, the release button locatedso as to permit a user of the device to ergonomically disengage thelocking mechanism.

The locking mechanism may include a clutch mechanism. The device mayinclude an engagement mechanism spring configured to press theengagement mechanism toward the second position. The locking mechanismmay include a locking pin. The device may include a locking pin springconfigured to press the locking pin toward the engagement mechanism. Theengagement mechanism may include a slot, and the locking pin may includea blade configured to engage the slot in the engagement mechanism whenthe engagement mechanism is in the first position. The release buttonmay be configured to disengage the blade from the slot. The device mayinclude a lid having a closed position and an open position, the lid maybe configured to retain the syringe within the handle in the closedposition, the lid further may be configured to release the syringe fromthe handle in the open position, a hinge pin may be configured toconnect the lid to the handle, and at least one ball plunger may beconfigured to releasably hold the lid in the closed position. The devicemay include a lid having a closed position and an open position, the lidmay be configured to retain the syringe within the handle in the closedposition, the lid further configured to release the syringe from thehandle in the open position, a hinge pin may be configured to attach thelid to the handle, a lid pin may be located in a side of the lid and maybe configured to fit into a corresponding hole in the handle, therebyretaining the lid in the closed position, and a lid spring may beconfigured to press the lid in a direction substantially parallel to thelid pin, the spring further configured to retain the lid pin in itscorresponding hole until released by a user of the device. The lidspring may be a coil spring, and the lid spring may surround at least aportion of the hinge pin.

A method for opening the lid of the device when the lid pin is insertedinto its corresponding hole may include sliding the lid along the hingepin to compress the lid spring, the sliding resulting in extraction ofthe lid pin from its corresponding hole, rotating the lid about thehinge pin so that the lid pin is not aligned with its correspondinghole, and sliding the lid along the hinge pin until the lid spring is nolonger compressed. A method may include placing the engagement mechanismin the second position, placing the syringe into the handle, moving theengagement mechanism to the first position, locking the engagementmechanism in the first position with the locking mechanism, dispensingbiomaterial, and relieving injection pressure in the syringe byoperating the release button.

Additional features, advantages, and embodiments of the disclosure maybe set forth or apparent from consideration of the following detaileddescription, drawings, and claims. Moreover, it is to be understood thatboth the foregoing summary of the disclosure and the following detaileddescription are exemplary and intended to provide further explanationwithout limiting the scope of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure, are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosure andtogether with the detailed description serve to explain the principlesof the disclosure. No attempt is made to show structural details of thedisclosure in more detail than may be necessary for a fundamentalunderstanding of the disclosure and the various ways in which it may bepracticed. In the drawings:

FIG. 1 shows an exploded view of a cement gun, according to an aspect ofthe disclosure;

FIG. 2 shows a cutaway view of the cement gun of FIG. 1;

FIG. 3A shows a side view of the cement gun of FIG. 1;

FIG. 3B shows a cross-section view of the cement gun of FIG. 3A alongline B-B with the engagement pin in a disengaged position;

FIG. 3C shows a cross-section view of the cement gun of FIG. 3A alongline B-B with the engagement pin in an engaged position;

FIG. 4 shows an exploded view of a cement gun according to an alternateaspect of the disclosure;

FIGS. 5A, 5B, and 5C show the operation of the lid of the cement gun ofFIG. 4;

FIG. 6 shows the cradle of the cement gun of FIG. 4;

FIGS. 7A and 7B show a cross-section view and rear view, respectively,of the cement gun of FIG. 4 with the engagement mechanism in an engagedposition;

FIGS. 8A and 8B show a cross-section view and rear view, respectively,of the cement gun of FIG. 4 with the engagement mechanism in adisengaged position;

FIG. 9A shows a cross-section view of the cement gun of FIG. 4 with theengagement mechanism in an engaged position;

FIG. 9B shows a cross-section view of the cement gun of FIG. 4 with theengagement mechanism in a disengaged position;

FIGS. 10A, 10B, 10C, and 10D show a clutch mechanism according to anadditional aspect of the disclosure;

FIGS. 11A, 11B, 12, 13A, and 13B show additional clutch mechanismsaccording to aspects of the disclosure; and

FIGS. 14 and 15 show further clutch mechanisms according to aspects ofthe disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

The embodiments of the disclosure and the various features andadvantageous details thereof are explained more fully with reference tothe non-limiting embodiments and examples that are described and/orillustrated in the accompanying drawings and detailed in the followingdescription. It should be noted that the features illustrated in thedrawings are not necessarily drawn to scale, and features of oneembodiment may be employed with other embodiments as the skilled artisanwould recognize, even if not explicitly stated herein. Descriptions ofwell-known components and processing techniques may be omitted so as tonot unnecessarily obscure the embodiments of the disclosure. Theexamples used herein are intended merely to facilitate an understandingof ways in which the disclosure may be practiced and to further enablethose of skill in the art to practice the embodiments of the disclosure.Accordingly, the examples and embodiments herein should not be construedas limiting the scope of the disclosure, which is defined solely by theappended claims and applicable law. Moreover, it is noted that likereference numerals represent similar parts throughout the several viewsof the drawings.

FIG. 1 shows an exploded view of an aspect of the disclosure. Accordingto this aspect of the disclosure, a cement gun 100 may include a handle101 and an engagement pin 102 that fits into a hole 103 in the handle101. The handle 101, engagement pin 102, and related parts may be madeof titanium; steel, including surgical stainless steel; metal; plastic;or a like material that allows the cement gun 100 to be repeatedlysterilized. The components of cement gun 100 may be coated or treated tobe antibacterial, antimicrobial, or the like.

The engagement pin 102 may be retained in the handle with a locking pin104 that fits into a groove (not shown) in the engagement pin 102. Thelocking pin 104 may be permanently affixed to the handle 101 by, e.g.,welding, epoxy, adhesive, glue, compression, riveting, or the like. Themating of the locking pin 104 to the groove permits the engagement pin102 to travel from side-to-side while still being retained within thehandle 101.

In particular, the engagement pin 102 may travel back-and-forth betweenan engaged position and a disengaged position, described in detailbelow. To prevent or reduce the likelihood of the engagement pin 102shifting between these positions except when so desired by the user, thehandle 101 may incorporate two ball plungers 105. The ball plungers 105may include a ball and spring construction. The ball plungers 105 may bealigned with one of two notches 107 (shown in FIGS. 3B, 3C) in theunderside of the engagement pin 102. For example, the ball plunger 105associated with the engaged position of the engagement pin 102 mayengage the notch 107 associated with the engaged position. Thisengagement may retain the engagement pin 102 in the engaged position,preventing it from spontaneously shifting to a different (i.e.disengaged) position. When the engagement pin is, e.g., in the engagedposition, the ball plunger 105 associated with the disengaged positionis not aligned with the notch 107 associated with the disengagedposition.

Handle 101 may receive a syringe assembly 120, which may include athreaded plunger 121. The handle 101 may also be fitted with a lid 130to secure and retain the syringe assembly 120. The lid 130 may have asecure closure for retaining the syringe assembly 120 within the handle.According to an aspect of the disclosure, the lid 130 may be attached tothe handle 101 with a hinge pin 132. The hinge pin 132 creates an axisof rotation along one side of the lid 130. The axis is such that the lid130 may be rotated up and away from the handle 101 to permit easy andquick removal and/or insertion of a syringe assembly 120. The lid 130may then be rotated down to a closed position for use.

As shown in FIG. 1, the lid 130 may be fitted with two ball plungers 131on corners distant from the hinge pin 132, although more or fewer ballplungers may be used without departing from the spirit and scope of thedisclosure and claims. The ball plungers may include a ball and a springconstruction. When the lid 130 is in a closed position, the ballplungers 131 may align with notches, cutouts, holes, or the like (notshown) in the handle 101. The ball plungers 131 may retain the lid 130in the closed position during normal use and operating conditions.

To facilitate opening the lid 130, the lid 130 may have an overhang orlip 133 on the side opposite the lid hinge 132 (shown in FIGS. 3A, 3B).This lip or overhang 133 may provide purchase or leverage, making iteasier for a user to open the lid 130 than it would be if the edge ofthe lid was more flush with the side of the handle.

According to an alternate aspect of the disclosure, handle 101 may befitted with the push-type lid as described below with respect to FIGS.4, 5A, 5B, and 5C.

FIG. 2 shows a cross-section view of the cement gun 100, while FIG. 3Ashows an external side view of the cement gun 100. FIG. 3B shows acutaway view taken along line B-B in FIG. 3A with the engagement pin 102in a disengaged position. FIG. 3C shows a cross-section view taken alongline B-B in FIG. 3A with the engagement pin in an engaged position.Engagement pin 102 contains a cutout 106 with one or more grooves thatmay be structured and arranged to engage the threads of the threadedplunger 121 of the syringe assembly 120. As shown in FIG. 1, the groovesare only located along one side of the cutout 106. When the engagementpin 102 is in a disengaged position, as shown, e.g., in FIG. 3B, thegrooves do not engage the threaded plunger 121. When the engagement pin102 is in an engaged position, as shown, e.g., in FIG. 3C, the groovesengage the threads of the plunger 121. Since the syringe 120 contains nomating threads of its own for the plunger 121, the plunger 121 can onlybe advanced by twisting when it is seated in the handle 101 and theengagement pin 102 is in an engaged position.

Since bone cement can be a very viscous material, it may be necessary tocreate substantial pressure inside the syringe assembly to force thebone cement through the narrow opening in the syringe. A surgeon orother user of the cement gun may create this pressure by placing theengagement pin 102 in an engaged position and turning the handle of thethreaded plunger 121 until a desired flow of bone cement is achieved. Ifit becomes necessary to cease the flow of bone cement for any reason,the user may simply slide the engagement pin to the disengaged position.Since there are no other groves or threads holding the plunger inposition, the pressure inside in the syringe assembly 120 may cause theplunger to slide partially out of the syringe, thereby relieving theinjection pressure and stopping the flow of bone cement.

As shown in FIGS. 1, 2, and 3A, the engagement pin 102 may be locatedjust above the grip of handle 101. This provides a location for theengagement pin 102 that may be very ergonomic for users of the cementgun 100. In this sense and as used herein, “ergonomic” and“ergonomically” mean that the elements are designed so as to minimize orreduce a user's physical effort and discomfort, thereby maximizing orimproving efficiency. For example, a right-handed user of the cement gun100 as shown in FIG. 3C may be able to easily slide the engagement pin102 from the engaged position to the disengaged position with a simplemovement of his thumb. A left-handed user may be able to disengage theengagement pin 102 with her index finger. The index finger, however, maynot be as effective at disengaging the pin 102 as the thumb. Dependingon the force required to disengage pin 102, it may be desirable toprovide a left-handed model of the cement gun 100 with the grooves onthe opposite side of cutout 106. This configuration may permit aleft-handed surgeon and other user to disengage the engagement pin 102with his thumb.

FIG. 4 shows an exploded view of a cement gun of an alternate aspect ofthe disclosure. According to this aspect, a cement gun 200 may include ahandle 201 and an engagement mechanism 202. The engagement mechanism 202may fit into a hole 203 in the handle 201. The handle 201, engagementmechanism 202, and related parts may be made of titanium; steel,including surgical stainless steel; metal; plastic; or a like materialthat allows the cement gun 200 to be repeatedly sterilized. Thecomponents of cement gun 200 may be coated or treated to beantibacterial, antimicrobial, or the like.

The engagement mechanism 202 may be retained in handle 201 with a dowelpin 204 that fits into a groove (not shown) in the engagement mechanism202. The dowel pin 204 may be permanently affixed to the handle 201 by,e.g., welding, epoxy, adhesive, glue, compression, riveting, or thelike. The mating of the dowel pin 204 to the groove permits theengagement mechanism 202 to travel from side-to-side while still beingretained within the handle 201.

The engagement mechanism 202 may be retained in an engaged position by alocking mechanism, such as, e.g., a locking pin 211. The engagementmechanism 202 may be disengaged by using a release button 209 to releasethe locking mechanism. The engagement mechanism 202 may include a cutoutwith one or more grooves or threads 206. The engagement mechanism 202may be mated with a spring 208 to press or bias the engagement mechanism202 toward a disengaged position. Spring 208 may be held in place with aretaining pin 213, which may fit into a corresponding hole or socket(not shown) in handle 201.

Handle 201 may receive a syringe assembly 220, which may include athreaded plunger 221. The handle 201 may also be fitted with a lid 230to secure and retain the syringe assembly 220. A lid 230 with a secureclosure is critical for retaining the syringe assembly 220 within thehandle. According to an aspect of the disclosure, a lid 230 may beattached to the handle 201 with a hinge pin 232. The hinge pin 232creates an axis of rotation along one side of the lid 239. The axis issuch that the lid 230 may be rotated up and away from the handle 201 topermit easy and quick removal and/or insertion of a syringe assembly220. The lid 230 may then be rotated down to a closed position for use.

As shown in FIG. 4, lid 230 may include a lid pin 234 along one side ofthe lid 230. Lid pin 234 may be inserted into a corresponding hole orsocket (not shown) in handle 201 to retain lid 230 in a closed position.A user may insert lid pin 234 into its corresponding socket by firstplacing lid 230 in a closed position, with pin 234 aligned with itshole, and then sliding lid 230 in the direction of the lid pin 234 andits hole. To keep lid pin 234 in its hole and keep lid 230 in a closedposition, a spring 233 may press against lid 230 to press or bias thelid 230 in the direction of lid pin 234 and its hole. Spring 233 may bea coil spring and may be fitted over hinge pin 232 such that hinge pin232 passes through the interior diameter of the coil.

FIGS. 5A, 5B, and 5C show steps for opening lid 230. In FIG. 5A, lid 230is in a closed position, with lid pin 234 inserted into itscorresponding hole or socket. The user of the cement gun 200 slides thelid away from pin 234. As shown in FIG. 5B, spring 233 may be compressedin the process. Lid pin 234 is now clear of its hole, and lid 230 may berotated to an open position, such as shown in FIG. 5C.

According to an alternate aspect of the disclosure, handle 201 may befitted with a ball plunger-type lid as described above with respect toFIG. 1.

FIG. 6 shows how a flange 222 of the syringe assembly 220 that may fitinto the cradle 214 of the handle 201.

FIG. 7A shows a cross-section view of the cement gun 200 with theengagement mechanism 202 locked in the engaged position by the lockingmechanism, in this case a locking pin 211. FIG. 7B shows a rear view ofthe cement gun 200 of FIG. 7A. With the engagement mechanism 202 in theengaged position, the groove or threads 206 in the cutout are meshedwith the threads on the threaded plunger 221 of the syringe assembly220. The locking mechanism in this aspect of the disclosure is a lockingpin 211 with a flat portion or blade 215 at its uppermost end. The blade215 fits into a groove 216 in the bottom of the engagement mechanism202, locking the engagement mechanism 202 into place in the engagedposition. A release button 209 is affixed to the rear of the handle 201and connected to the locking pin 211 with a screw 210, although othermeans of connecting the release button 209 to the locking pin arecontemplated and are within the spirit and scope of the disclosure. Aspring 212 may be located beneath the locking pin 211 to press or biasthe locking pin 211 toward the engagement mechanism 202.

FIG. 8A shows a cutaway view of the cement gun 200 with the locking pin211 disengaged from the engagement mechanism 202, and FIG. 8B shows arear view of the cement gun 200 of FIG. 8A. To release the engagementmechanism from the engaged position, a surgeon or other user of thecement gun 200 may slide the release button 209 downward, e.g., to theposition shown in FIGS. 8A and 8B. Since the release button 209 isconnected to the locking pin 211, the locking pin also moves down untilthe blade 215 is clear of its groove 216 in the underside of theengagement mechanism 202. In some aspects, the engagement mechanism 202may have a spring 208 to bias the mechanism 202 away from the engagedposition and toward a disengaged position. Thus, when the blade 215 isfully removed from its groove 216, the engagement mechanism may snap orpop to a disengaged position. Disengaging locking pin 211 compressesspring 212, which in turn biases or presses locking pin 211 toward oragainst the underside of the engagement mechanism 202. When engagementmechanism 202 is returned to an engaged position and the blade 215aligns with its groove 216 in the engagement mechanism 202, spring 212may press locking pin 211 upward so that the blade 215 engages thegroove 216 and locks the engagement mechanism 202 in the engagedposition.

Release button 209 may be ergonomically located on the handle 201, asshown e.g. in FIGS. 7A, 7B, 8A, and 8B. In this configuration, the userof the cement gun 200 may disengage the locking mechanism by sliding therelease button 209 down with his thumb. This configuration may beoperated with equal efficiency by both right-handed and left-handedusers.

FIGS. 9A and 9B show rear cross-section views of the locking pin 211 andengagement mechanism 202 in locked and unlocked positions, respectively.In FIG. 9A, the threads or grooves 206 of the engagement mechanism 202are meshed with the threads of the threaded plunger 221. Spring 208 iscompressed, pressing or biasing mechanism 202 away from its current,engaged, position. The engagement mechanism 202, however, is held in theengaged position by virtue of the blade 215 of the locking pin 211,which is inserted into groove 216 on the underside of the engagementmechanism 202. With the parts in this configuration, the surgeon or userof the cement gun 200 may increase injection pressure inside the syringeby turning the handle or knob of the threaded plunger 221.

If the user needs to quickly relieve the injection pressure, he simplyslides the ergonomically located release button 209 down. Release button209 is connected to locking pin 211 and thus moves the locking pin 211downward as well. As shown in FIG. 9B, when the locking pin has traveledsufficiently downward, the blade 215 is removed from the groove 216.Spring 208 is now able to press the engagement mechanism 202 to theright, thereby disengaging threads 206 from threaded plunger 221. Spring208 retains proper alignment with engagement mechanism 202 thanks toretaining pin 213.

FIGS. 10A, 10B, 10C, and 10D show a clutch mechanism 300 that may beused as a locking mechanism for the cement gun 200 in place of thelocking pin 211 described above. Clutch 300 may include a fixed pivot305 that may be fixed in place relative to the threaded plunger 306.Fixed pivot 305 may join a pair of jaws 310 a, 310 b and allow them torotate relative to one another. Jaws 310 are connected to arms 304 bypivots 307, and arms 304 are connected to clutch pin 308 by pivots 303.Clutch pin 308 may be biased or pressed upwards by spring 301. Thisupward pressure on clutch pin 308 translates into pressure to close jaws310. Jaws 310 may include threads or grooves to engage threads onthreaded plunger 306. In this way, jaws 310 provide the same function asengagement mechanism 202, as shown in FIGS. 10A and 10C. To open thejaws 310 and, e.g., quickly relieve injection pressure, a user may pressdown on release button 302. This motion compresses spring 301, moves pin308 downwardly, and opens jaws 310, as shown in FIGS. 10B and 10D.

FIGS. 11A, 11B, 12, 13A, and 13B show alternate aspects of a clutchmechanism. Clutches 400, 410, and 420 are all naturally biased toward aclosed or gripping position without an external spring, such as, e.g.,spring 301. In FIG. 11A, clutch 400 has a central pivot 403. Pressing onthe clutch loop 404, as shown in FIG. 11B, may cause the jaws 402 ofclutch 400 to open, releasing its grip on threaded plunger 401. Clutch410, shown in FIG. 12, is similar to clutch 400 but lacks the centralpivot. As shown in FIG. 13A, Clutch 420 is formed from a continuouspiece of material, such as metal, looped across itself, crossing atcrossover point 422, to give the proper bias to the jaws 421. Clutch 420may open its jaws 421 by compressing clutch loop 423, as for clutches400 and 410. Alternatively, a sliding mechanism 424, as shown in FIG.13B, may have the same effect compress loop 423. All three clutch typesare compatible with a release button mechanism, similar in operation tothose shown for cement gun 200 and clutch 300, as will be understood byone having ordinary skill in the art without undue experimentation.

FIGS. 14 and 15 show additional aspects of a clutch mechanism. Clutch500 is similar to clutch 400 in that it has a central pivot 509, loop501, and jaws 507. The jaws 507 of clutch 500, however, may beconfigured to provide a cradle 506 for syringe 502 and flange 503, inaddition to gripping the threaded plunger 504 with threads or grooves505. Clutch 500 may also include a locking mechanism 508 to hold theclutch in a closed or gripping position.

Clutch 600 is similar to clutch 420 in that it uses a crossover point tocreate bias. Clutch 600 may also have a clutch loop 601 and jaws 602,but the jaws 602 may be configured to provide a cradle 603 for syringe607 and flange 606, in addition to gripping threaded plunger 605 withgrooves or threads 604. Both clutch 500 and clutch 600 are compatiblewith a release button mechanism, similar in operation to those shown forcement gun 200 and clutch 300, as will be understood by one havingordinary skill in the art without undue experimentation.

While the disclosure has been described in terms of exemplaryembodiments, those skilled in the art will recognize that the disclosurecan be practiced with modifications in the spirit and scope of theappended claims. These examples given above are merely illustrative andare not meant to be an exhaustive list of all possible designs,embodiments, applications or modifications of the disclosure.

1. A device for dispensing biomaterial, the device comprising: a handleconfigured to receive a syringe, the syringe comprising a biomaterialand a threaded plunger; and an engagement pin retained within the handleand slidable between a first position and a second position, theengagement pin configured to engage the threaded plunger in the firstposition; the engagement pin further configured to disengage from thethreaded plunger in the second position.
 2. The device of claim 1,further comprising a hole in the handle, the hole configured to hold theengagement pin, the hole located so as to permit a user of the device toergonomically slide the engagement pin between the first position andthe second position.
 3. The device of claim 1, further comprising: alocking pin configured to retain the engagement pin within the hole; andat least one ball plunger configured to releasably hold the engagementpin in at least one of the first position and the second position. 4.The device of claim 1, further comprising: a lid having a closedposition and an open position, the lid configured to retain the syringewithin the handle in the closed position, the lid further configured torelease the syringe from the handle in the open position; a hinge pinconfigured to connect the lid to the handle; and at least one ballplunger configured to releasably hold the lid in the closed position. 5.The device of claim 1, further comprising: a lid having a closedposition and an open position, the lid configured to retain the syringewithin the handle in the closed position, the lid further configured torelease the syringe from the handle in the open position; a hinge pinconfigured to attach the lid to the handle; a lid pin located in a sideof the lid and configured to fit into a corresponding hole in thehandle, thereby retaining the lid in the closed position; and a lidspring configured to press the lid in a direction substantially parallelto the lid pin axis, the spring further configured to retain the lid pinin its corresponding hole until released by a user of the device.
 6. Thedevice of claim 5, wherein: the lid spring is a coil spring; and the lidspring surrounds at least a portion of the hinge pin.
 7. A method foropening the lid of the device of claim 5 when the lid pin is insertedinto its corresponding hole, the method comprising: sliding the lidalong the hinge pin to compress the lid spring, the sliding resulting inextraction of the lid pin from its corresponding hole; rotating the lidabout the hinge pin so that the lid pin is not aligned with itscorresponding hole; and sliding the lid along the hinge pin until thelid spring is no longer compressed.
 8. A method for using the device ofclaim 1, the method comprising: placing the engagement pin in the secondposition; placing the syringe into the handle; sliding the engagementpin to the first position to engage the threaded plunger; dispensingbiomaterial; and relieving injection pressure in the syringe by slidingthe engagement pin to the second position.
 9. A device for dispensingbone cement, the device comprising: a handle configured to receive asyringe, the syringe comprising a biomaterial and a threaded plunger; anengagement mechanism contained within the handle and having a firstposition and a second position, the engagement mechanism configured toengage the threaded plunger in the first position; the engagementmechanism further configured to disengage from the threaded plunger inthe second position; a locking mechanism configured to releasably lockthe engagement mechanism in the first position; and a release buttonconfigured to disengage the locking mechanism, thereby releasing theengagement mechanism from the first position, the release button locatedso as to permit a user of the device to ergonomically disengage thelocking mechanism.
 10. The device of claim 9, wherein the lockingmechanism comprises a clutch mechanism.
 11. The device of claim 9,further comprising an engagement mechanism spring configured to pressthe engagement mechanism toward the second position.
 12. The device ofclaim 9, wherein the locking mechanism comprises a locking pin.
 13. Thedevice of claim 12, further comprising a locking pin spring configuredto press the locking pin toward the engagement mechanism.
 14. The deviceof claim 12, wherein: the engagement mechanism comprises a slot; and thelocking pin comprises a blade configured to engage the slot in theengagement mechanism when the engagement mechanism is in the firstposition.
 15. The device of claim 14, wherein the release button isconfigured to disengage the blade from the slot.
 16. The device of claim9, further comprising: a lid having a closed position and an openposition, the lid configured to retain the syringe within the handle inthe closed position, the lid further configured to release the syringefrom the handle in the open position; a hinge pin configured to connectthe lid to the handle; and at least one ball plunger configured toreleasably hold the lid in the closed position.
 17. The device of claim9, further comprising: a lid having a closed position and an openposition, the lid configured to retain the syringe within the handle inthe closed position, the lid further configured to release the syringefrom the handle in the open position; a hinge pin configured to attachthe lid to the handle; a lid pin located in a side of the lid andconfigured to fit into a corresponding hole in the handle, therebyretaining the lid in the closed position; and a lid spring configured topress the lid in a direction substantially parallel to the lid pin, thespring further configured to retain the lid pin in its correspondinghole until released by a user of the device.
 18. The device of claim 17,wherein: the lid spring is a coil spring; and the lid spring surroundsat least a portion of the hinge pin.
 19. A method for opening the lid ofthe device of claim 17 when the lid pin is inserted into itscorresponding hole, the method comprising: sliding the lid along thehinge pin to compress the lid spring, the sliding resulting inextraction of the lid pin from its corresponding hole; rotating the lidabout the hinge pin so that the lid pin is not aligned with itscorresponding hole; and sliding the lid along the hinge pin until thelid spring is no longer compressed.
 20. A method for using the device ofclaim 9, the method comprising: placing the engagement mechanism in thesecond position; placing the syringe into the handle; moving theengagement mechanism to the first position; locking the engagementmechanism in the first position with the locking mechanism; dispensingbiomaterial; and relieving injection pressure in the syringe byoperating the release button.